Means for removing dents from sheet metal surfaces



Sept. 11, 1934- o. L. CALLAHAN MEANS FOR REMOVING DENTS FROM SHEET llE'l l'AL SURFACES Filed Oct. 6, 1932 2 Sheets-Sheet l INVENTOR. am/ 5. Kaila/2am u AWI )0 ATTORNEY.

Sept. 11, 1934. Q 1 CALLAHAN 1,973,331

, MEANS FOR REMOVING DEN'I'S FROM SHEET METAL SURFACES Filed Oct. 6, 1932 2 Sheets-Sheet 2 Q m; w v INENTOR. aize/ L CaZZa&a1/&

A TTORNEY.

aienteci Sept. 11, 1934 PATENT oFFica MEANS FOR REMOVING DENTS FROM SHEET METAL SURFACES Oscar L. Callahan, West Frankfort, Ill., asslgnor of one-half to George I. Cutter, West Frankfort, Ill.

Application October 6, 1932, Serial No. 636,542

15 Claims. (01. 153-32) This invention relates to a device for removing dents from sheet metal surfaces, and one form of the device, as illustrated, is particularly adapted for the removing of dents and like defects 5 from automobile fenders, or mud guards.

The broad principle of operation on which the invention is based is well known from the standpoint of hand operation, and I am unaware of any attempts havingbeen made to practically l apply it by the use of a pneumatic tool.

It is an object of the invention to improve the method of removing dents from sheet metal surfaces by new and novel means, with a view to facilitation and simplification of its operation, and to this end, I provide a device which is simple in construction, comparatively inexpensive, practical, positive and efficient in operation, and, further well adapted for the purposes designed.

The object of the invention is to carry out a 20 simple method of removing dents from sheet metal surfaces in an expeditious manner.

A characteristic feature of the invention, briefly stated, is the entire absence of manual operation of the device in carrying out the method of removing dents from sheet metal surfaces, excepting the mereholding of the device for directing its operations.

The more specific objects of the invention will appear more clearly from the following description read in connection with the accompanying drawings, in which:

Fig. 1 is a view in side elevation of the device as used for removing dents from sheet metal surfaces, such for one instance, as an automobile fender, or mud guard. The device is shown in full lines in operative position and in dotted lines in inoperative position.

Fig. 2 is a detail of the buffer end of one of the arms of the device.

Fig. 3 is a view showing one side of a control device.

Fig. 4 is a view of the control device partly in sectional elevation and partly in plan view.

Fig. 5 is a detail of the lower end of the control device. I

Fig. 6 is a sectionalview of an air hammer forming apart of the device.

Fig. '7 is a plan view of the device.

Fig. 8 is a side elevation of one part of the device which constitutes a frame member, as detached from the other member of the frame, and which is capable for use as a tool for cutting, gouging, hammering and similar and other obvious purposes, too numerous to mention.

Fig. 9 is a view showing a modified way of atdle 3.

taching the air hammer to one of the frame members of the device.

In carrying out the aim of my present invention for applying my improved method of removing or smoothing out dents in sheet metal surfaces, I employ a' suitably shaped frame designated generally as A, and which comprises a pair of suitable arms designated 1 and 2. Arm 1, which is shown as substantially straight, but which may, if desired, be of any-other desired shape, is preferably, although not necessarily, in the nature of a tubular member for the sake of lightness and strength, but may be of solid material, if desired. The arm 1 is provided at one end with a suitable handle 3 for gripping the tool with one hand, while the other hand is adapted to grip the frame member, or arm 1. The opposite end of arm 1 is provided-with a suitable pneumatic device, or air hammer designated, generally as B, and which device is shown. as disposed with its longitudinal axis at a right angle to the longitudinal axis of the arm 1, although it may be disposed at any other angle, if deemed advisable without departing from the principle of the invention. One principle of such a change can be ascertained from the modification shown in Fig. 9, wherein the air hammer, or device B, is pivoted, as at 4, to cars, or arms 5 directed from one end of the arm 1, so that the air hammer may be moved to any desired adjusted position relative to the arm 1., even to lying in axial alignment with the arm 1, and the hammer device is locked in this instance in any of its adjusted positions by a suitable locking device 6.

The arm 2 is suitably shaped, or bent, so that the frame as a whole will appear as c-shaped, when the two parts are assembled. The arm. 2 is pivotally connected at one end, as at 7, to the arm 1, intermediate the hammer B and the ham- The opposite or free end of the frame arm 2 is provided with a suitable buffer member, or tool head 8 which is recessed, as at 9, to receive the free end of arm 2 and a suitable resilient member 10 disposed in the recess 9" between the closed end thereof and the end face, or edge of the arm 2. The head a is swivelly mounted on the end of the arm 2 and is held against accidental removal therefrom by means of a suitable resilient expander key ring like locking member 10' seated 05 on one side in a recess 11 in the wall of the recess 9 so as to engage below a flange 12 on the end of the arm 2, as clearly shown in Fig. 2. The

arm 2 is so shaped that when the two arms of the frame are assembled, and the device is in opera- 110 tive position relative to a dented sheet metal member C, the tool head 8 will bedisposed op-, posite a suitable metal shaping tool head 13 reciprocably mounted by means of a shank 14 on one end of the pneumatic hammer B.

Supported by and depending from the arm 1 is a suitable housing 15, which is suitably fixed at its upper edges to the arm 1, as at 16 by wedging, or the like, as shown in Fig. 8. A suitable cylinder 17, open at one end is adjustably connected at its opposite'end to the wall 18 of the housing 15 by means of a suitable screw threaded stud 19 on the closed end of cylinder 1'1. The stud 19 passes through a slotted opening 20 in the wall 18 and is secured in its adjusted position by means of a suitable locking device 21. v

The cylinder 17 isdisposed to the rear. of the arm 2, and within the, housing 15, as shown in Fig. 1, and the cylinder is provided with a suitable loose. piston 22, having suitable expansible cap 23 onits inner end. The outer end or the piston 22 is provided with a suitable lug, or protuberance 24 adapted for operative engagement with a suitable plate 25 on the rear side of the arm 2 disposed a suitable distance. below-the pivot '7. The function of the piston 22 is to exert pressure, during operation of the device, against the plate on arm 2 to move the arm 2 from its normally open position, as shown in dotted lines in Fig. 1, to its operative or closed position, as shown in Fig. 1, thus bringing the buffer toolhead 8 up to and in engagement with theside of the dented metal member C opposite to that which is tappingly engaged to the shaping tool head 13.

A chamber 26 is formed within the cylinder 17 between the. closed end thereof and the cap 23 on the inner end of the piston. The chamber 26 communicates with the chamber of the pneumatic hammer B, as hereinafter described, through the medium of a suitable flexible conduit 27. The chamber 26 also communicates, through the medium of a suitable flexible conduit 28, with a suitable valve designated generally as D, and a suitable flexible conduit 29, the latter connected with a suitable tank 30, or other suitable source of supply filled with compressed air.

The valve structure D interposed between the conduits 28 and-29, is shown as comprising a cas-- ing 31 carried by a suitable support 31 and having suitable connection with the conduit 29 through a suitable fitting 32, and with the conduit 28 through a suitable fitting 33. Associated with fitting 32 is a suitable spring closed ball valve 34 mounted in a recess 35 and normally closing one end of suitable air passage 36 which is normally open to a recess 37 within which recess a suitable spring closed ball valve'38 is mounted, but normally held open by means of a suitable pin 39,

which moves the ball valve out of seated engagement with the inner end of an exhaust opening 40 communicating at its inner end with the recess 37 and at its outer .end with the atmosphere. A suitable pin 41 is employed for unseating the ball valve 34 and the pins 39 and 41 are acted upon by means of suitable cam faces 42 and 43, respec tively, on a suitable lever 44, pivoted as at 45 to the valve casing 31 and having suitable connection, at one end, with a spring raised, foot depressed headed stem 46. When the foot depressed stem 46 is in its raised position, the pin 39 is moved inward to unseat the ball valve 38 and open the exhaust opening 40 and the pin 41 is retracted by the seating of the ball valve 34, and,

when the stem 46 is depressed, the pin 41 is moved applicable to the herein described device.

A hammer B' for actuating the same to impart successive blows or taps through the tool head 13 to the dented surface of a sheet metal article. will be here observed, that as the compressed air enters the chamber 26 of cylinder 17, that the piston 22 is moved outward for raising the arm 2 and the head 8 thereon so that the head 8 will be held in engagement with the dented article on the opposite face thereof to that which the tool head 8 has successive tapping engagement with due to the action of the air hammer B.

The specific air hammer illustrated in the drawings, is the subject matter of an application filed by me April 30th, 1932, bearing serial number 608,471, Patent No. 1,940,388, dated December 19, 1933, therefore aside from stating that the air hammer includes a plunger 47 provided with a pair of peripheral recesses 48 and 49 of diiferent widths communicating with opposite ends of the piston through suitable port openings from conduit 27 enters the'piston recesses, and,

having two fluid outlets 54 through which the fluid is exhausted after performing its duty, further description of the hammer is believed .unnecessary as other types of air hammers are also It will be observed that reciprocating movement of the piston imparts successive tapping to the shank 14 of the tool head 13. I

By means of the device herein described, it is readily obvious that the operatorthereof does not have to display and exert any muscular strength to smooth out the dents in'metal surfaces, but merely holds the device in the desired positions while the air hammer applies the necessary force to remove the dents, which dents, as is apparent, are disposed between the cushioned tool and the reciprocable tool actuated by the air hammer.

It is believed that the operation of the device is obvious from the drawings, and the description thereof herein, hence further description as to the operation of the device is believed unnecessary.

It may here be stated, however, that when it is desired to use the air hammer and any suitable tool to be reciprocated thereby, as for cutting operations, gouging operations, hammering operations and similar or unsimilar operations, the arm 2 can be removed from arm 1, as shown in Fig, 8, by removing the pivot pin '7 and this same pin can then be usedas a stop for the piston 22 by first retracting the piston to the position shown in dotted lines in Fig. 1, and then inserting the pin in an opening 55 in the wall of the cylinder 23 and into an opening 56 in the piston, or in any equivalent manner which will prevent the piston from being discharged from the cylinder when air pressure is applied therebehind.

From Fig. 1 of the drawings, and the foregoing member: that the hinged or pivoted arm of the frame is moved into and-held in operative position relative to the air hammer by the actionof the piston which is responsive to air pressure, thus m the hinged arm of the frame also. in reality, responsive to air pressure. when the air pressure is released from the air hammer, it is also rel from behind the piston and the arm impurtsrapid successive blows or taps to the dented surfnce opposite a suitable cushioned tool which is capable of swivel movement as the device is moved into various positions on the dented surface in removing the dents from such surface.

2-: i I have shown and described in this application the use of a pneumatic i s a part of the frame thereof, it will be obvious that other to of pneumatic hammers may be usedtherewith. It will also be obvious that the specific old,

dill

construction of boiler shaping element used, the shape of arm to which it is applied and the shaping element reciprocated by the pneumatiehammer may be modified without departing from the salient features of the invention, and also that the m shown as ntrolling the fluid under pressure may be m ed. It is also observed that the device may be separated so that one part of the frame and its associated parts may be used, without the other arm and buffer member thereof for other purposes than smoothing out dents in metal surfaces. 1

e advantages of the herein described:

method of smoothing out dents in metal surfaces will readily suggest themselves to those skilled in the art to which it appertains. at l cl is: i

i. in a sheet metal dent remo mec ,Y m, :1; a ed fro-me including two luneedly connected members, o berember on the free end of one of the to members, o plunger responsive to air pressureue A w one end of the latter frnme memher to move said member into operative position, menus responsive to sir pressure disposed opno on boner member for imparting rspid imposts to the dented arcs of the motel disposed between the louder member and the menus responsive to pressure. Si, in o metal dent removing innehine, the combinntion oi a frame buying a straight member and n ll=-shnned member godly connected at one end to the straight member, cushioned butler member on sold U=sbuned member, sold ll-shaped member being responsive to air pressure, and moons resnonsive to eir'pressure for setting up a rapid succession oi. blows opposite the buder member. s 7

3. A mochine of tho character described, the combination of the following instrumentalities, on approximately o-shaned ironic including two members hingedly coected, one oi sold members being" straight, a linndle on one end of the straight member, reciprocating means responsive to air pressure on the opposite end of said member, a

eoned buffer on the free end of the other ram ember opposite the reciprocating means, sold letter member being responsive to air pressure nnd o, headed frame member responsive to tot m intermediate the ends of the other am so that said reciprocating means for impartingnimpag to said headed member. .1 4. In a device for removing dents from sheet metal, suchas automobile fenders and the like, the combination of a frame including two hinged members, a handle on one of said frame members, reciprocable means responsive to air pressure. a

buffer member on the other frame member, said latter frame member being responsive to air pressure, impact means on the handled member and disposed opposite saidbufler member for imparting successive blows to a: dented sheet metal surface disposed between the bufler member and said impact means, said impact means being responsive to the reciprocable means which is responsive to air pressure and means for controlling the air pressure.

5. A tool for some indented sheet metal articles including a frame having two arms, one

of said arms being pivotally connected at one end the frame can straddle thearticle, means responsive' to air pressure carried by one arm of the frame for rapidly tapping the indented portion of the article anda cushioned blufler carried by the pivoted arm of the frame for engaging the indented article opposite the tapping means and means adjacent the pivoted arm for moving it into and holding the same in operative position during operation of the means responsive to 1 5 air pressure. 7

6. A tool for smoothing indented sheet metal articles including a. frame having two arms hingedly connected for straddling the article, means responsive to air pressure carried by one arm of the frame for rapidly tapping the indented portion of the article, a cushioned buil'er carried by the other arm of the frame for engaging the indented article opposite the tapping means and means responsive to air pressure for moving said latter arm in one direction and holding the some in wor position.

7. A device for removing indentations from sheet metal suices including a portable frame formed of pivotelly connected arms which are 1% adapted to straddle the indented portion of the sheet motel and. movable toward and sway from such other, comnlemental dent smoothing elements applied to solid arms in opposed relation to each other, one oi sold elements being resiliently 12b and swivelly supported on one of the srms of the home, sold erm being responsive to air pressure for ov the some into operative position, means responsive to air pressure on the other mm or the ire and the other'of said elements curried by the sold orm being responsive to sold moons.

d. A device for nothing out indentetions from sheet metal articles including o portuble frame hnving two hingedly connected arms or; a vnriable opening permitting the frnme to stroddle the metel erticle and to be shifted in very or directions to the locations of the indented area of the article, on air beer on one end of one of the arms oithe fro, opposing shaping elel ments, one of sold elements being resiliently and swivelly mounted on the free end of the other 3!, iltli of the frame, said letter frame arm being responsive to movement in one direction under air pressure end means for controlling the air M5 pressure.

9. In n machine of the character described, the combination of the following instnmientolities, a o-shoped frame including two members hineedly rying opposing dent removing members and said a handle on one end of said straight member, a reciprocating member responsive to air pressure on the opposite end of the straight member, a cushioned buffer on the free end of the other frame member, a slidable member adjacent said latter frame member and responsive to movement in one direction by air pressure and a shaping member responsive to said reciprocating member for imparting successive impacts to said' shaping member.

. 10. In a device for removing dents from sheet metal, such as automobile mud guards and the like, the combination of a frame including two hingedly connected frame members, a handle on one end of one of the frame members, reciprocable means responsive to air pressure on the opposite end of said frame member, a buffer member on the free end of the other frame member, said latter frame member being responsive to air pressure for movement into operative position, impact means actuated by said means responsive to air pressure and valve mechanism for controlling the means responsive to air pressure.

11. A device for smoothing out indented sheet metal articles including a portable frame carframe being shaped to permit tilting movements thereof relative to the article to be worked upon, means reciprocably responsive to air pressure on one end of the frame adjacent one of the dent removing members for imparting successive blows thereto and the other of said dent removing members being resiliently and swivelly supported on the end of said frame opposite the first dent removing member and means responsive to air pressure for moving the resiliently and swivelly supported dent removing member into operative position.

12. A sheet metal dent removing device having, in combination, a handle member, an air hammer on one end of said handle member, an impact member actuated by said air hammer, an arm pivoted tosaid handle member, a buffer on the free end of said arm and disposed opposite the impact member, a cylinder, a support for said cylinder connected to said handle member, an air conduit leading from said cylinder to said air hammer, an air controlled valve, a conduit leading from said valve to said cylinder, a con-' 13. A sheet metal dent removing device having, in combination, an air hammer including an impact member, a handle member for supporting said hammer on one end thereof, a buffer in co-acting relation to the impact member, a. buffer supporting member, a pivotal connection between one end of the buffer supporting member and said hammer supporting handle member, a support connected to the hammer supporting handle member adjacent said pivotal connection, a cylinder having an open endadjustably connected to said support, a piston responsive to air pressure mounted in said cylinder and having one end thereof projecting beyond the open end of said cylinder for contact with the buffer supporting member adjacent said pivotally connected end thereof for moving the buffer member into and holding the same in operative position during operation of the air hammer.

14. In a device of the class described including a straight frame member, an air hammer on one end of said frame member and including a working tool, a second frame member including a metal shaping member for one end thereof, said frame member being detachably pivoted at its opposite end to said first frame member, a support depending from said first frame member adjacent the pivoted end of said second frame member, a cylinder connected to said support and disposed between the support and the pivoted end of the second frame member, a plunger mounted in the cylinder responsive to air pressure to contact with, move and hold the second frame member in operative position relative to the first frame member when the air hammer is in operation, and a movable member for holding the plunger in its innermost position in the cylinder when it is desired to remove the second frame member from the first frame member and use the first frame member and air hammer independent of the second frame member.

15. In an apparatus for removing dents in sheet metal surfaces, an air hammer, a support for the air hammer, a shaping element actuated by the air hammer, a member pivoted to said support, a buffer member supported by the pivoted member, a slidable member responsive to air pressure adapted to move and hold the pivoted member in operative position during dent removing operations and a support for said slidable member.

OSCAR L. CALLAHAN. 

